Magnetic control of surface states

ABSTRACT

A magnetic field may be applied to a plasmon path to affect plasmon propagation.

SUMMARY

In one embodiment, a method comprises: inducing a surface state signalat a first location; defining a propagation path for the surface state,independently of a separate path-defining structure, by imposing aspatially-varying magnetic field configured to produce aspatially-varying permittivity, the propagation path extending from thefirst location to a second location spatially separated from the firstlocation; and selectively controlling propagation of the surface statealong the propagation path by selectively controlling thespatially-varying magnetic field.

In another embodiment, an apparatus comprises: a first surface statesupport including an input location and an output location; and a firstmagnetically responsive structure interposed at a first central locationintermediate the input location and the output location, the firstmagnetically responsive structure being responsive to aspatially-varying magnetic field to produce a spatially-varyingpermittivity proximate to the first surface state support to controlsurface state propagation independently of a separate path-definingstructure.

In another embodiment, a system comprises: a first plasmon routedefining region including a magnetically interactive portion responsiveto a first magnetic field to define a propagation route of a firstplasmon signal absent a separate routing structure.

In another embodiment, an apparatus comprises: a first surface statesupport including an input location and an output location, the firstsurface state support being defined by a boundary between a firstmaterial and a second material, wherein each of the first material andthe second material is optically thick; and a first magneticallyresponsive structure interposed at a first central location intermediatethe input location and the output location, the first magneticallyresponsive structure being responsive to a magnetic field to controlsurface state propagation by establishing a first permittivity proximateto the first surface state support.

In another embodiment, an apparatus comprises: a first photonic crystalsurface state support including an input location and an outputlocation, wherein the first photonic crystal surface state supportincludes an interface between a first photonic crystal and a secondmaterial; and a first magnetically responsive structure interposed at afirst central location intermediate the input location and the outputlocation, the first magnetically responsive structure being responsiveto a magnetic field to control surface state propagation by establishinga first permittivity proximate to the first photonic crystal surfacestate support.

In another embodiment, a method comprises: inducing a surface state at afirst input location; defining a propagation path for the surface stateby imposing a spatially-varying magnetic field having a first non-zerodistribution, wherein the first non-zero distribution has a firstnon-zero magnitude B1 at a first magnetic field location r1 on thepropagation path and a second non-zero magnitude B2 at a second magneticfield location r2 on the propagation path, the first spatially-varyingmagnetic field being configured to produce a spatially-varyingpermittivity, the propagation path extending from the first inputlocation to a first output location spatially separated from the firstinput location; and varying the propagation path by changing the firstspatially-varying magnetic field to a second magnetic field having asecond non-zero distribution, wherein the second non-zero distributionhas a third non-zero magnitude B3 at the first magnetic field locationr1 and a fourth non-zero magnitude B4 at the second magnetic fieldlocation r2, and wherein the ratio of B4/B3 is different from the ratioof B2/B1.

In another embodiment, an apparatus comprises: a first surface statesupport including an input location and at least two output locations;and at least one magnetically responsive structure interposed at leastone first central location intermediate the input location and the atleast two output locations, the at least one magnetically responsivestructure being responsive to a magnetic field to block surface statepropagation to at least one of the at least two output locations.

In another embodiment, a method comprises: coupling a first surfacestate mode in a first dielectric region to a second surface state modein a second dielectric region, the first dielectric region and thesecond dielectric region being at least partially overlapping; andvarying said coupling of the first surface state, mode to the secondsurface state mode by applying a first magnetic field to at least one ofthe first region and the second region.

In another embodiment, a method comprises: varying the coupling betweena surface state M a first dielectric region and a radiative mode byvarying a magnetic field applied to the first dielectric region, theapplied magnetic field being configured to vary the permittivity of atleast a portion of the first dielectric region.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a surface state at a boundary.

FIG. 2 shows an array of particles.

FIG. 3 shows a photonic band gap diagram.

FIG. 4 shows a first photonic crystal structure including a firstmaterial and a second material.

FIG. 5 shows an apparatus including a surface state support and amagnetically responsive structure.

FIG. 6 shows an apparatus including a surface state support and amagnetically responsive structure.

FIG. 7 shows a system including a plasmon route defining region.

FIG. 8 shows a side cross-section of an apparatus comprising a firstsurface state support.

FIG. 9 a shows an apparatus supportive of a surface state, and amagnetic field.

FIG. 9 b shows an apparatus supportive of a surface state, and amagnetic field.

FIG. 10 shows an apparatus comprising a surface state support includingan input location and two output locations and two magneticallyresponsive structures.

FIG. 11 shows an apparatus supportive of a surface state mode that iscoupled to a second surface state mode.

FIG. 12 a shows a surface state support including a conductor and adielectric region.

FIG. 12 b shows a surface state support including a photonic crystal, afirst dielectric region, and a second dielectric region.

FIG. 12 c shows a surface state support including a photonic crystal anda first dielectric region.

FIG. 13 is a flow chart depicting a method.

FIGS. 14-17 depict variants of the flow chart of FIG. 13.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented here.

Surface states may exist on a boundary between two materials when thereal parts of their dielectric constants ∈ and ∈′ have different signs,for example between a metal and a dielectric. FIG. 1 shows a surfacestate 102 at a boundary 104 of a material 106 having a negative realdielectric constant, such as a metal. The material or structure 108forming the boundary 104 with the material 106 may be: air, vacuum, orits equivalent; a substantially homogeneous dielectric material; or adifferent material or structure. The boundary 104, although shown asbeing substantially continuous and planar, may have a different shape.The surface state 102, although shown as including substantiallyexponential functions with a field maximum at the boundary 104, mayinclude only approximately exponential functions, may be described by adifferent function, and/or may have a field maximum someplace other thanthe boundary. Further, although the surface state 102 is shown at acertain location on the boundary 104 for illustrative purposes, thespatial distribution of the surface state 102 may be anything. Surfacestates are described in C. Kittel, “INTRODUCTION TO SOLID STATEPHYSICS”, Wiley, 2004, which is incorporated herein by reference.

In some embodiments the material thickness 110 may be smaller than thesurface state wavelength, as described in Alexandra Boltasseva, ThomasNikolajsen, Krisjan Leosson, Kasper Kjaer, Morten S. Larsen, and SergeyI. Bozhevolnyi, “INTEGRATED OPTICAL COMPONENTS UTILIZING LONG-RANGESURFACE PLASMON POLARITONS”, Journal of Lightwave Technology, January,2005, Volume 23, Number 1, which is incorporated herein by reference.Further, Boltasseva describes how a metal may be embedded in adielectric to allow propagation of long-range surface plasmonpolaritons, where the parameters of the metal [including thickness 110and width (not shown)] may control the propagation of the plasmon.

Particles 202 may be configured to support and guide surface states,where the particles 202 shown in FIG. 2 are silver spheres. Particlessupporting surface states are described in M. Salerno, J. R. Krenn, B.Lamprecht, G. Schider, H. Ditlbacher, N. Félidj, A. Leitner, and F. R.Aussenegg, “PLASMON POLARITONS IN METAL NANOSTRUCTURES: THEOPTOELECTRONIC ROUTE TO NANOTECHNOLOGY”, Opto-Electronics Review, 2002,Volume 10, Number 3, pages 217-222, which is incorporated herein byreference. Creation of surface states on a particle in anelectromagnetic field is described in P. G. Kik, A. L. Martin, S. A.Maier, and H. A. Atwater, “METAL NANOPARTICLE ARRAYS FOR NEAR FIELDOPTICAL LITHOGRAPHY”, Proceedings of SPIE, 4810, 2002 which isincorporated herein by reference. FIG. 2 shows electromagnetic energy206 incident on a chain of particles 202, where the electromagneticenergy 206 couples to surface states 102 on the particles 202. Thesurface states 102 are shown having a finite extent in FIG. 2 forclarity and one skilled in the art will recognize that the spatialdistribution of the surface states 102 may fall off according to a powerlaw away from the particles 202 and/or may have a different distributionthan that shown in FIG. 2. Particles 202 may be configured on asubstrate (not shown), as described in Stefan A. Maier, Paul E. Barclay,Thomas J. Johnson, Michelle D. Friedman, and Oskar Painter, “LOW-LOSSFIBER ACCESSIBLE PLASMON WAVEGUIDE FOR PLANAR ENERGY GUIDING ANDSENSING”, Applied Physics Letters, May 17, 2004, Volume 84, Number 20,Pages 3990-3992, which is incorporated herein by reference.

Although the particles 202 in FIG. 2 are shown as being substantiallyspherical, the particles may have a different shape that is configuredto support surface states. Further, although the particles 202 are shownas being substantially the same size, the particles 202 may vary insize, by design or by a randomized process of manufacturing theparticles 202. Moreover, the particles need not be homogenous or evensolid. Also, although the particles 202 are described as silverparticles, particles 202 that support surface states may comprise adifferent metal or a different material. Although the particles 202 areillustrated as having a spacing between particles 208 that issubstantially constant, the spacing may vary and may be different fromthat shown in FIG. 2, and in some embodiments, the particles 202 may betouching or very nearly so.

A surface state may exist on a dielectric-dielectric interface where oneof the dielectrics has a negative, or effectively negative,permittivity. For example, where one or both of the dielectrics is amaterial having a band gap, such as a photonic crystal, a surface statemay exist at the interface between the photonic crystal and the otherdielectric in the forbidden energy bands of the photonic crystal.Photonic crystals are described in E. Yablonovitch, “PHOTONIC CRYSTALS:SEMICONDUCTORS OF LIGHT”, Scientific American, December 2001, Volume285, Number 6, pages 47-55, which is incorporated herein by reference.

A band gap diagram with band gap 302 is shown in FIG. 3. The photoniccrystal may be a 1D, 2D, or 3D photonic crystal as described inYablonovitch. A photonic crystal may guide surface states as describedin A. I. Rahachou and I. V. Zozoulenko, “WAVEGUIDING PROPERTIES OFSURFACE STATES IN PHOTONIC CRYSTALS”, Linkoping University, Departmentof Science and Technology, bearing a date of Oct. 31, 2005, pages 1-4and located athttp://www.itn.liu.se/meso-phot/publications/2005_waveguides_(—)0510273.pdf,which is incorporated herein by reference and a copy of which isattached hereto as Appendix A.

FIG. 4 shows a surface state 102 at a boundary 104 of a first photoniccrystal structure 401. The material or structure (not shown) forming theboundary 104 with the first photonic crystal structure 401 may be: air,vacuum, or its equivalent; a substantially homogeneous dielectricmaterial; a second photonic crystal structure; or a different materialor structure. The boundary 104, although shown as being substantiallycontinuous and planar, may have a different shape. The surface state102, although shown as including substantially exponential functionswith a field maximum at the boundary 104, may include only approximatelyexponential functions, may be described by a different function, and/ormay have a field maximum someplace other than the boundary 104. Further,although the surface state 102 is shown at a certain location on thefirst photonic crystal structure 401 for illustrative purposes, thespatial distribution of the surface state 102 may be anything.

FIG. 4 shows a first photonic crystal structure 401 including a 1Dphotonic crystal comprising layers of a first material 402 and a secondmaterial 404 fabricated on a substrate 406. Examples of 1D photoniccrystals are given in Yablonovitch and in Y. Fink, J. N. Winn, S. Fan,C. Chen, J. Michel, J. D. Joannopoulos, and E. L. Thomas, “A DIELECTRICOMNIDIRECTIONAL REFLECTOR”, Science, Nov. 27, 1998, Volume 282, pages1679-1682, which is incorporated herein by reference.

Although the first photonic crystal structure 401 is shown havingalternating layers of a first material 402 and a second material 404,where the layers have substantially equal thicknesses, the layerthicknesses and materials 402, 404 may be chosen according to the designof the first photonic crystal structure 401, and the layer thicknessesmay vary. For example, the design of the first photonic crystalstructure 401 may be such that the layer thicknesses are configured tovary, the layer thicknesses may vary slightly due to fabricationimperfections, the structure may include a top layer having a thicknessinconsistent with the periodicity of the remainder of the first photoniccrystal structure 401, and/or there may be other reasons for variationsin the layer thicknesses. Although the first photonic crystal structure401 is shown including two different materials 402, 404, it may includemore than two types of materials. Further, although the first photoniccrystal structure 401 is shown having seven layers in FIG. 4, it mayhave a different number of layers. The first photonic crystal structure401 in FIG. 4 is shown as a 1D photonic crystal for exemplary purposes,but in other embodiments the first photonic crystal structure 401 may bea 2D or 3D photonic crystal structure, and may have variations analogousto those described for a 1D photonic crystal structure.

In some embodiments, a magnetic field may control surface statepropagation, as described in, “MAGNETOPLASMA SURFACE WAVES IN METALS”,K. W. Chiu and J. J. Quinn, Physical Review B, pages 4707-4709, Volume5, Number 12, June 1972, which is incorporated herein by reference. Forexample, as shown in FIG. 5, an apparatus 500 comprises a first surfacestate support 502 including an input location 504 and an output location506, and a first magnetically responsive structure 508 interposed at afirst central location 510 intermediate the input location 504 and theoutput location 506, the first magnetically responsive structure 508being responsive to a spatially-varying magnetic field 512 to produce aspatially-varying electromagnetic property proximate to the firstsurface state support 502 to control surface state propagationindependently of a separate path-defining structure. In someembodiments, the spatially-varying electromagnetic property may be aspatially-varying permittivity.

In this embodiment the input location 504 and the output location 506include gratings 512, 514, where the gratings 512, 514 are configured toconvert electromagnetic energy to plasmon energy. The gratings 512, 514are just one example of a structure for converting electromagneticenergy to plasmon energy, and other structures may be used, such as anarray of particles, or a different structure. Further, although theinput and output locations 504, 506 in FIG. 5 are configured to receiveelectromagnetic energy, in other embodiments the input and outputlocations 504, 506 may be arranged to receive surface state energy.

The spatially-varying electromagnetic property may vary as a function offrequency, and specifically, the spatial variation of theelectromagnetic property may occur over a first frequency range, wherethe first frequency range may overlap (wholly or partially) with asecond frequency range, where the second frequency range includes thefrequencies of the surface states. The first and/or second frequencyranges may include, for example, optical frequencies or other frequencyranges.

The first surface state support 502 may include a material 106 having anegative real dielectric constant, such as a metal, a semiconductor,and/or a photonic crystal structure, as described with respect to FIGS.1 and 4.

In FIG. 5, the first magnetically responsive structure 508 issubstantially integral to the first surface state support 502. Howeverin some embodiments the magnetically responsive structure 508 may formonly a portion of the first surface state support 502. For example, aportion of the first surface state support 502 may include amagnetically responsive material. Further, although the first surfacestate support 502 is shown as being substantially homogeneous, in otherembodiments it may not be, such as in cases where the first surfacestate support is patterned.

In the embodiment shown in FIG. 5, the spatially-varying magnetic field512 is shown as, being substantially uni-directional and as having amagnitude that varies substantially monotonically in one direction.However, in other embodiments the direction and/or magnitude of themagnetic field 512 may have a different configuration. For example, themagnetic field 512 may have a magnitude which is substantially constantand a direction which varies spatially. There are many differentconfigurations of magnetic field 512 that may be produced to create thedesired effect on the apparatus 500.

FIG. 6 shows an apparatus similar to that of FIG. 5, wherein the firstsurface state support 502 includes an array of particles 602. In thisembodiment, as well as that shown in FIG. 5, the magnetically responsivestructure 508 is shown as being substantially integral to the firstsurface state support 502, i.e., in this embodiment each of theparticles 604 in the array of particles 602 is magnetically responsive,such that the entire first surface state support 502 forms themagnetically responsive structure. This need not be the case, however,and in other embodiments the first surface state support 502 may includeportions that are supportive of a surface state 102 but are notmagnetically responsive.

In the embodiment of FIG. 6, the array of particles 602 is asubstantially homogeneous array, wherein each of the particles 604 inthe array 602 is substantially the same size and comprises substantiallythe same material or materials. The particles 602 in the array 604 areconfigured to respond to an applied magnetic field 610 to change theireffective permittivity. In this way, the magnetic field 610 applied toparticles 604 in the array 602 can select a path 606 (depicted by shadedparticles) for plasmon energy.

As shown in FIG. 6, electromagnetic energy 608 is incident on a particle604 having a magnetic field 610 applied to it. The magnitude anddirection of the incident magnetic field 610 is selected such that itchanges the permittivity of the particles 604 along the path 606 suchthat they support plasmon energy having an energy that is equivalent tothat of the electromagnetic energy 608. The plasmon energy thenpropagates along the path 606 of the particles 604 that support plasmonsof that energy.

The array of particles 602 shown in FIG. 6 is substantiallytwo-dimensional, however in other embodiments the array may besubstantially three-dimensional or one-dimensional.

In the embodiment of FIG. 7, a system comprises a first plasmon routedefining region 702 (analogous to the first surface state support 502 ofFIGS. 5 and 6) including a magnetically interactive portion 703(analogous to the first magnetically responsive structure 508 of FIGS. 5and 6) responsive to a first magnetic field 610 to define a propagationroute 705 (depicted by shaded particles and analogous to the path 606 ofFIG. 6) of a first plasmon signal absent a separate routing structure.

In this embodiment, the first plasmon route defining region 702 includesan array of particles 602 that are supportive of plasmon energy and aresufficiently proximate to one another to transmit plasmon energy totheir nearest-neighbors. Further, the magnetically interactive portion703, in the embodiment of FIG. 7, includes all of the particles 604 inthe array. The operation is similar to that shown in FIG. 6, wherein thefirst magnetic field 610 is configured to determine the propagationroute 705 of the first plasmon signal.

Although the embodiment of FIG. 7 is shown such that the first plasmonroute defining region 702 includes an array of particles 604, in otherembodiments the first plasmon route defining region 702 may have adifferent configuration. For example, in some embodiments the firstplasmon route defining region 702 may include a substantially continuoussurface such as the first surface state support 502 shown in FIG. 5.Although two different types of plasmon route defining regions 702 areshown here as exemplary embodiments, in other embodiments the firstplasmon route defining region 702 may have a different configuration.

In this embodiment, magnetic field sources 704 are configured to producethe first magnetic field 610. The embodiment further comprises aprocessor, wherein the processor is operably coupled to the magneticfield sources 704 to turn them on or off. Further, in this embodimenteach of the particles 604 in the array that form the first plasmon routedefining region 702 is responsive to a magnetic field, such that theentire first plasmon route defining region 702 is also the magneticallyinteractive portion 703. However, in other embodiments the magneticallyinteractive portion 703 may form just a part of the first plasmon routedefining region 702.

In some embodiments, the magnetic field sources 704 may beelectromagnets, permanent magnets, a mixture of both, or a differentkind of magnet.

The distribution and direction of the first magnetic field 610 shown inFIG. 7 is one exemplary embodiment and many other magnetic fielddistributions may be employed depending on the application. For example,the magnetic field strength and direction may vary spatially. Or, aconfiguration inverse to that shown in FIG. 7 may be employed, wherein amagnetic field is applied to areas (for example, particles 604) wherethe plasmon is prohibited from propagating by moving the particle 604off of plasmon resonance, and the plasmon signal propagates along theparticles 604 that do not have a magnetic field 610 applied to them.These are just a few examples of how the embodiment of FIG. 7 may beadjusted according to a particular design, and one skilled in the artmay tailor the design for their purposes.

In the exemplary embodiment of FIG. 7, the processor 708 is shown asbeing operably coupled to each of the magnetic field sources 704 and thesource of input energy 706. However, in some embodiments the processor708 may be operably coupled to more or less components than is shown inFIG. 7. For example, the processor 708 may be operably coupled to anarray including thousands of magnetic field sources 704, and/or theprocessor may be operably coupled to elements configured to moveportions of the system, such as MEMS devices configured to move themagnetic field sources, or other devices configured to provide motion toone or more of the components shown in FIG. 7.

FIG. 8 shows a side cross-section of an apparatus 800 comprising a firstsurface state support 502 including an input location 504 and an outputlocation 506, the first surface state support 502 being defined by aboundary 104 between a first material 802 and a second material 804,wherein each of the first material 802 and the second material 804 isoptically thick; and a first magnetically responsive structure 508interposed at a first central location 510 intermediate the inputlocation 504 and the output location 506, the first magneticallyresponsive structure 508 being responsive to a magnetic field 806 tocontrol surface state propagation by establishing a first permittivityproximate to the first surface state support 502. The apparatus 800 issimilar to that of FIG. 5, where FIG. 5 does not explicitly show thesecond material 804.

Generally, in this embodiment and the other embodiments presented inFIGS. 1-17, the input location 504 and the output location 506 may beconfigured to receive electromagnetic energy, surface state energy,and/or a different type of energy. For example, where the input location504 and/or the output location 506 are configured to receiveelectromagnetic energy as in FIG. 5, the input location and/or theoutput location 506 may include a grating 512, 514 or other structureconfigured to convert the electromagnetic energy into surface stateenergy. In this embodiment the first magnetically responsive structure508 is integral to the first material 802 and the second material 804.As described in Chiu et al., applying a magnetic field such as 806 to aconfiguration supportive of a surface state 102 may change theproperties of the surface state 102, thereby allowing control of thesurface state 102 via the application of a magnetic field 806. Thespatial distribution of the magnetic field 806 may be selected such thatit steers a surface state that propagates along the boundary 104.

The first material 802 and the second material 804 include materialswhose real dielectric constants have opposite signs. For example, thefirst material 802 may include a metal and the second material 804 mayinclude a dielectric. Different configurations supportive of surfacestates have been described in more detail with reference to FIGS. 1-4.

The magnetic field 806 in FIG. 8 is shown as being substantiallyconstant in magnitude and direction. However, this magnetic field 806 isshown for illustrative purposes, and in other embodiments the magneticfield 806 may vary in magnitude and/or direction, may vary temporally,and/or may vary in a different way.

In this embodiment, optically thick is defined such that the thicknesses808, 810 of the first and second material 802, 804 are great enough thatthe amplitude of a surface state 102 excited on one side of either thefirst material 802 or the second material 804 will be less than 1/100thof its maximum on the other side of the material. Although thethicknesses 808, 810 are shown as being substantially constant along thelength of the apparatus 800, in some embodiments the thicknesses 808,810 may vary, along the length of the apparatus and/or along anotherdimension, such as the width.

In some embodiments the first material 802 may include a photoniccrystal. In this case the second material 804 may include: a dielectric;a photonic crystal different from that of the first material 802; and/ora different type of material. Further, the boundary 104 may form aphotonic crystal surface state support.

FIGS. 9 a and 9 b show an apparatus 900 on which a surface state 102 isinduced at a first input location 504. As shown in FIG. 9 a, apropagation path 901 for the surface state 102 is defined by imposing aspatially-varying magnetic field 902 having a first non-zerodistribution, wherein the first non-zero distribution has a firstnon-zero magnitude B₁ (904) at a first magnetic field location r₁ (906)on the propagation path 901 and a second non-zero magnitude B₂ (908) ata second magnetic field location r₂ (910) on the propagation path 901,the first spatially-varying magnetic field 902 being configured toproduce a spatially-varying permittivity, the propagation path 901extending from the first input location 504 to a first output location506 spatially separated from the first input location 504. Thepropagation path 901 may further be varied by changing the firstspatially-varying magnetic field 902 to a second magnetic field 912,shown in FIG. 9 b, having a second non-zero distribution, wherein thesecond non-zero distribution has a third non-zero magnitude B₃ (914) atthe first magnetic field location r_(i) (906) and a fourth non-zeromagnitude B₄ (916) at the second magnetic field location r₂ (910), andwherein the ratio of B4/B3 is different from the ratio of B2/B1.

The apparatus 900 is similar to those shown in FIGS. 5 and 8, and FIGS.9 a and 9 b show how the spatial distribution of a magnetic field (suchas 902 and/or 912) may vary, spatially and/or temporally. Thisvariation, however, is just one exemplary embodiment, and there are manyways in which a magnetic field (such as 902 and/or 912) may vary,spatially and/or temporally, and there are many ways in which a varyingmagnetic field may control surface state energy.

Although the spatially-varying magnetic field 902 and the secondmagnetic field 912 are shown spanning the entire distance between thefirst input location 504 and the first output location 506, in otherembodiments the magnetic fields 902 and/or 912 may span only a portionof the distance between the first input location 504 and the firstoutput location 506. Further, although only one input location 504 andone output location 506 are shown, other embodiments may include morethan one input location 504 and/or more than one output location 506.Further, although the spatially-varying magnetic field 902 and thesecond magnetic field 912 are shown having a magnitude varying along onedirection, in other embodiments it may vary in two or three orthogonaldirections. The spatially-varying magnetic field 902 and the secondmagnetic field 912 may vary monotonically, non-monotonically, or in adifferent way. Or, the magnitude of the second magnetic field 912 may besubstantially constant. The direction of the spatially-varying magneticfield 902 and/or the second magnetic field 912 may vary, along with orinstead of the magnitudinal variation.

FIG. 10 shows a top view of an apparatus comprising a first surfacestate support 1002 including an input location 504 and two outputlocations (1004 and 1006); and two magnetically responsive structures(1008 and 1010) interposed at central locations (1012, 1014)intermediate the input location 504 and the two output locations (1004,1006), the magnetically responsive structures (1008, 1010) beingresponsive to a magnetic field 806 to block surface state propagation toat least one of the two output locations 1008 and 1010.

The surface state support 1002, although shown as being substantiallycontinuous, may not be continuous, and may include, for example, anarray of particles 202, as shown in FIGS. 2, 6, and 7.

Further, although FIG. 10 shows two branches 1016, 1018 and two outputlocations 1004, 1006, other embodiments may include more than twobranches 1016, 1018 and/or more than two output locations 1004, 1006.

The magnetically responsive structures 1008, 1010 may in some casesinclude a material different from the materials forming the remainder ofthe surface state support 1002, or the material may be the same as thatthat forms the remainder of the surface state support. For example,where the material forming the magnetically responsive structures 1008,1010 is the same as the materials forming the reminder of the surfacestate support 1002, a magnetic field 806 may be applied to one or bothmagnetically responsive structures 1008, 1010 to block propagation of asurface state 102 to one or both output locations 1004, 1006. However,where the material forming the magnetically responsive structures 1008,1010 is different from the material forming the remainder of the surfacestate support 1002, the magnetically responsive structures 1008, 1010may block surface state propagation with no magnetic field applied, andmay allow surface state propagation with a selected magnetic field.

Although the magnetically responsive structures 1008, 1010 are shownlocated at the bases of the branches 1016, 1018, in other embodimentsthe magnetically responsive structures 1008, 1010 may be located at adifferent place, such as further along on the branch, or in a differentembodiment there may only be one magnetically responsive structurelocated at the branching location of the branches 1016, 1018 that isconfigured to pass or block surface state propagation to both branches1016, 1018 simultaneously.

FIG. 11 shows an apparatus supportive of a first surface state mode 1102in a first dielectric region 1104, where the first surface state mode1102 is coupled to a second surface state mode 1106 in a seconddielectric region 1108, the first dielectric region 1104 and the seconddielectric region 1108 being at least partially overlapping. In thisembodiment, the coupling of the first surface state mode 1102 and thesecond surface state mode 1106 may be varied by applying a firstmagnetic field 1110 to at least one of the first region 1104 and thesecond region 1108.

The magnetic field 1110 in FIG. 11 is shown as being substantiallyconstant in magnitude and direction. However, this magnetic field 1110is shown for illustrative purposes, and in other embodiments themagnetic field 1110 may vary in magnitude and/or direction, may varytemporally, and/or may vary in a different way.

The first and second dielectric regions 1104, 1106 are described by anoval shape in FIG. 11, however this is for illustrative purposes only,as the surface state mode 1102 decays according to a power law away fromthe boundary 104.

FIGS. 12 a, 12 b, and 12 c show embodiments of apparatus (1202, 1204,and 1206) for varying the coupling between a surface state 102 in afirst dielectric region 1208 and a radiative mode 1209 by varying amagnetic field 806 applied to the first dielectric region 1208, theapplied magnetic field 806 being configured to vary the permittivity ofat least a portion of the first dielectric region 1208.

FIG. 12 a shows an embodiment having a conductor 1210 in intimatecontact with the first dielectric region 1208. The first dielectricregion 1208 is configured with a grating 1212 such that evanescentenergy proximate to the grating 1212 is converted into radiative energyin the radiative mode 1209. By varying the applied magnetic field 806,the spatial profile of the surface state 102 changes and it's couplingto the radiative mode 1209 changes.

FIG. 12 b shows an embodiment having a photonic crystal 1214 proximateto the first dielectric region 1208, wherein the first dielectric region1208 is proximate to a second dielectric region 1216. In the embodimentof FIG. 12 b, the first dielectric region 1208 has a variable dielectricconstant n₁(B) that is a function of an applied magnetic field 806,where n₁(B=0) allows plasmon propagation in a first frequency range, andwherein n₁(B=B₁)=n₂, where n₂ is the dielectric constant of the seconddielectric region 1216, and where n₂ prohibits plasmon propagation inthe first frequency range.

FIG. 12 c shows an embodiment having a photonic crystal 1214 proximateto the first dielectric region 1208, where in this case the firstdielectric region 1208 is selected to have a variable refractive indexn(B), where depending on the applied magnetic field 806, the refractiveindex n(B) may be such that it supports or does not support a surfacestate.

In one embodiment, depicted in the Flow Chart of FIG. 13, a methodcomprises: (1302) inducing a surface state signal at a first location;(1304) defining a propagation path for the surface state, independentlyof a separate path-defining structure, by imposing a spatially-varyingmagnetic field configured to produce a spatially-varying permittivity,the propagation path extending from the first location to a secondlocation spatially separated from the first location; and (1306)selectively controlling propagation of the surface state along thepropagation path by selectively controlling the spatially-varyingmagnetic field.

As depicted in the flow chart of FIG. 14, (1402) the spatially-varyingmagnetic field may include a static magnetic field, and/or (1404) thespatially-varying magnetic field may include a quasi-static magneticfield. (1306) Selectively controlling propagation of the surface statealong the propagation path by selectively controlling thespatially-varying magnetic field may further include (1406) steering thesurface state by selectively controlling the spatially-varying magneticfield. The method may further comprise (1408) temporally varying thespatially-varying magnetic field.

As depicted in the flow chart of FIG. 15, (1302) inducing a surfacestate signal at a first location may further include (1502) exciting aplasmon on at least one particle at the first location, wherein (1304)defining a propagation path for the surface state, independently of aseparate path-defining structure, by imposing a spatially-varyingmagnetic field configured to produce a spatially-varying permittivity,the propagation path extending from the first location to a secondlocation spatially separated from the first location, may furtherinclude (1504) applying a magnetic field to at least one particle alongthe propagation path. In some embodiments, (1504) the propagation pathmay be substantially one-dimensional, (1506) the propagation path may besubstantially two-dimensional, and/or (1508) the propagation path may besubstantially three-dimensional. In some embodiments, (1306) selectivelycontrolling propagation of the surface state along the propagation pathby selectively controlling the spatially-varying magnetic field mayfurther include (1512) reflecting the surface state by selectivelycontrolling the spatially-varying magnetic field.

As depicted in the flow chart of FIG. 16, (1602) the spatially-varyingmagnetic field may vary along substantially one direction, (1604) thespatially-varying magnetic field may vary along substantially twoorthogonal directions, and/or (1606) the spatially-varying magneticfield may vary along substantially three orthogonal directions. Themethod may further comprise (1608) generating the spatially-varyingmagnetic field, and (1610) changing the spatially-varying magnetic fieldto change the spatially-varying permittivity along the propagation path.

As depicted in the flow chart of FIG. 17, (1702) the surface state mayinclude plasmon energy, and/or (1704) the surface state may include aphotonic crystal surface state. In some embodiments, (1706) thespatially-varying permittivity may vary in a first frequency range, andthe surface state may have a second frequency range, wherein the firstfrequency range may overlap at least in part with the second frequencyrange. In some embodiments, (1708) the first frequency range may includeoptical frequencies, and/or (1710) the second frequency range mayinclude optical frequencies.

Although not explicitly shown in each figure, any of the embodimentsshown in FIGS. 1-17 may include system-level components as those shownin FIG. 7. Such components may include, for example, one or moremagnetic field sources 704, one or more sources of input energy 706,and/or one or more processors 708. The system shown in FIG. 7 includes asingle processor configured to control and/or receive information fromthe magnetic field sources 704 and the source of input energy 706.However, in other embodiments not every component may be operablyconnected to the processor, and/or each component may be connected to adifferent processor. When configuring a system, many differentarrangements including system-level apparatus may be selected to achievethe desired control and/or processing.

Those having skill in the art will recognize that the state of the arthas progressed to the point where there is little distinction leftbetween hardware, software, and/or firmware implementations of aspectsof systems; the use of hardware, software, and/or firmware is generally(but not always, in that in certain contexts the choice between hardwareand software can become significant) a design choice representing costvs. efficiency tradeoffs. Those having skill in the art will appreciatethat there are various vehicles by which processes and/or systems and/orother technologies described herein can be effected (e.g., hardware,software, and/or firmware), and that the preferred vehicle will varywith the context in which the processes and/or systems and/or othertechnologies are deployed. For example, if an implementer determinesthat speed and accuracy are paramount, the implementer may opt for amainly hardware and/or firmware vehicle; alternatively, if flexibilityis paramount, the implementer may opt for a mainly softwareimplementation; or, yet again alternatively, the implementer may opt forsome combination of hardware, software, and/or firmware. Hence, thereare several possible vehicles by which the processes and/or devicesand/or other technologies described herein may be effected, none ofwhich is inherently superior to the other in that any vehicle to beutilized is a choice dependent upon the context in which the vehiclewill be deployed and the specific concerns (e.g., speed, flexibility, orpredictability) of the implementer, any of which may vary. Those skilledin the art will recognize that optical aspects of implementations willtypically employ optically-oriented hardware, software, and or firmware.

In some implementations described herein, logic and similarimplementations may include software or other control structuressuitable to operation. Electronic circuitry, for example, may manifestone or more paths of electrical current constructed and arranged toimplement various logic functions as described herein. In someimplementations, one or more media are configured to bear adevice-detectable implementation if such media hold or transmit aspecial-purpose device instruction set operable to perform as describedherein. In some variants, for example, this may manifest as an update orother modification of existing software or firmware, or of gate arraysor other programmable hardware, such as by performing a reception of ora transmission of one or more instructions in relation to one or moreoperations described herein. Alternatively or additionally, in somevariants, an implementation may include special-purpose hardware,software, firmware components, and/or general-purpose componentsexecuting or otherwise invoking special-purpose components.Specifications or other implementations may be transmitted by one ormore instances of tangible transmission media as described herein,optionally by packet transmission or otherwise by passing throughdistributed media at various times.

Alternatively or additionally, implementations may include executing aspecial-purpose instruction sequence or otherwise invoking circuitry forenabling, triggering, coordinating, requesting, or otherwise causing oneor more occurrences of any functional operations described above. Insome variants, operational or other logical descriptions herein may beexpressed directly as source code and compiled or otherwise invoked asan executable instruction sequence. In some contexts, for example, C++or other code sequences can be compiled directly or otherwiseimplemented in high-level descriptor languages (e.g., alogic-synthesizable language, a hardware description language, ahardware design simulation, and/or other such similar mode(s) ofexpression). Alternatively or additionally, some or all of the logicalexpression may be manifested as a Verilog-type hardware description orother circuitry model before physical implementation in hardware,especially for basic operations or timing-critical applications. Thoseskilled in the art will recognize how to obtain, configure, and optimizesuitable transmission or computational elements, material supplies,actuators, or other common structures in light of these teachings.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, it will beunderstood by those within the art that each function and/or operationwithin such block diagrams, flowcharts, or examples can be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or virtually any combination thereof. In one embodiment,several portions of the subject matter described herein may beimplemented via Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Arrays (FPGAs), digital signal processors (DSPs), orother integrated formats. However, those skilled in the art willrecognize that some aspects of the embodiments disclosed herein, inwhole or in part, can be equivalently implemented in integratedcircuits, as one or more computer programs running on one or morecomputers (e.g., as one or more programs running on one or more computersystems), as one or more programs running on one or more processors(e.g., as one or more programs running on one or more microprocessors),as firmware, or as virtually any combination thereof, and that designingthe circuitry and/or writing the code for the software and or firmwarewould be well within the skill of one of skill in the art in light ofthis disclosure. In addition, those skilled in the art will appreciatethat the mechanisms of the subject matter described herein are capableof being distributed as a program product in a variety of forms, andthat an illustrative embodiment of the subject matter described hereinapplies regardless of the particular type of signal bearing medium usedto actually carry out the distribution. Examples of a signal bearingmedium include, but are not limited to, the following: a recordable typemedium such as a floppy disk, a hard disk drive, a Compact Disc (CD), aDigital Video Disk (DVD), a digital tape, a computer memory, etc.; and atransmission type medium such as a digital and/or an analogcommunication medium (e.g., a fiber optic cable, a waveguide, a wiredcommunications link, a wireless communication link (e.g., transmitter,receiver, transmission logic, reception logic, etc.), etc.).

In a general sense, those skilled in the art will recognize that thevarious embodiments described herein can be implemented, individuallyand/or collectively, by various types of electro-mechanical systemshaving a wide range of electrical components such as hardware, software,firmware, and/or virtually any combination thereof; and a wide range ofcomponents that may impart mechanical force or motion such as rigidbodies, spring or torsional bodies, hydraulics, electro-magneticallyactuated devices, and/or virtually any combination thereof.Consequently, as used herein “electro-mechanical system” includes, butis not limited to, electrical circuitry operably coupled with atransducer (e.g., an actuator, a motor, a piezoelectric crystal, a MicroElectro Mechanical System (MEMS), etc.), electrical circuitry having atleast one discrete electrical circuit, electrical circuitry having atleast one integrated circuit, electrical circuitry having at least oneapplication specific integrated circuit, electrical circuitry forming ageneral purpose computing device configured by a computer program (e.g.,a general purpose computer configured by a computer program which atleast partially carries out processes and/or devices described herein,or a microprocessor configured by a computer program which at leastpartially carries out processes and/or devices described herein),electrical circuitry forming a memory device (e.g., forms of memory(e.g., random access, flash, read only, etc.)), electrical circuitryforming a communications device (e.g., a modem, communications switch,optical-electrical equipment, etc.), and/or any non-electrical analogthereto, such as optical or other analogs. Those skilled in the art willalso appreciate that examples of electro-mechanical systems include butare not limited to a variety of consumer electronics systems, medicaldevices, as well as other systems such as motorized transport systems,factory automation systems, security systems, and/orcommunication/computing systems. Those skilled in the art will recognizethat electro-mechanical as used herein is not necessarily limited to asystem that has both electrical and mechanical actuation except ascontext may dictate otherwise.

In a general sense, those skilled in the art will recognize that thevarious aspects described herein which can be implemented, individuallyand/or collectively, by a wide range of hardware, software, firmware,and/or any combination thereof can be viewed as being composed ofvarious types of “electrical circuitry.” Consequently, as used herein“electrical circuitry” includes, but is not limited to, electricalcircuitry having at least one discrete electrical circuit, electricalcircuitry having at least one integrated circuit, electrical circuitryhaving at least one application specific integrated circuit, electricalcircuitry forming a general purpose computing device configured by acomputer program (e.g., a general purpose computer configured by acomputer program which at least partially carries out processes and/ordevices described herein, or a microprocessor configured by a computerprogram which at least partially carries out processes and/or devicesdescribed herein), electrical circuitry forming a memory device (e.g.,forms of memory (e.g., random access, flash, read only, etc.)), and/orelectrical circuitry forming a communications device (e.g., a modem,communications switch, optical-electrical equipment, etc.). Those havingskill in the art will recognize that the subject matter described hereinmay be implemented in an analog or digital fashion or some combinationthereof.

Those skilled in the art will recognize that at least a portion of thedevices and/or processes described herein can be integrated into animage processing system. Those having skill in the art will recognizethat a typical image processing system generally includes one or more ofa system unit housing, a video display device, memory such as volatileor non-volatile memory, processors such as microprocessors or digitalsignal processors, computational entities such as operating systems,drivers, applications programs, one or more interaction devices (e.g., atouch pad, a touch screen, an antenna, etc.), control systems includingfeedback loops and control motors (e.g., feedback for sensing lensposition and/or velocity; control motors for moving/distorting lenses togive desired focuses). An image processing system may be implementedutilizing suitable commercially available components, such as thosetypically found in digital still systems and/or digital motion systems.

Those skilled in the art will recognize that at least a portion of thedevices and/or processes described herein can be integrated into a dataprocessing system. Those having skill in the art will recognize that adata processing system generally includes one or more of a system unithousing, a video display device, memory such as volatile or non-volatilememory, processors such as microprocessors or digital signal processors,computational entities such as operating systems, drivers, graphicaluser interfaces, and applications programs, one or more interactiondevices (e.g., a touch pad, a touch screen, an antenna, etc.), and/orcontrol systems including feedback loops and control motors (e.g.,feedback for sensing position and/or velocity; control motors for movingand/or adjusting components and/or quantities). A data processing systemmay be implemented utilizing suitable commercially available components,such as those typically found in data computing/communication and/ornetwork computing/communication systems.

Those skilled in the art will recognize that it is common within the artto implement devices and/or processes and/or systems, and thereafter useengineering and/or other practices to integrate such implemented devicesand/or processes and/or systems into more comprehensive devices and/orprocesses and/or systems. That is, at least a portion of the devicesand/or processes and/or systems described herein can be integrated intoother devices and/or processes and/or systems via a reasonable amount ofexperimentation. Those having skill in the art will recognize thatexamples of such other devices and/or processes and/or systems mightinclude—as appropriate to context and application—all or part of devicesand/or processes and/or systems of (a) an air conveyance (e.g., anairplane, rocket, helicopter, etc.), (b) a ground conveyance (e.g., acar, truck, locomotive, tank, armored personnel carrier, etc.), (c) abuilding (e.g., a home, warehouse, office, etc.), (d) an appliance(e.g., a refrigerator, a washing machine, a dryer, etc.), (e) acommunications system (e.g., a networked system, a telephone system, aVoice over IP system, etc.), (f) a business entity (e.g., an InternetService Provider (ISP) entity such as Comcast Cable, Qwest, SouthwesternBell, etc.), or (g) a wired/wireless services entity (e.g., Sprint,Cingular, Nextel, etc.), etc.

In certain cases, use of a system or method may occur in a territoryeven if components are located outside the territory. For example, in adistributed computing context, use of a distributed computing system mayoccur in a territory even though parts of the system may be locatedoutside of the territory (e.g., relay, server, processor, signal-bearingmedium, transmitting computer, receiving computer, etc. located outsidethe territory).

A sale of a system or method may likewise occur in a territory even ifcomponents of the system or method are located and/or used outside theterritory.

Further, implementation of at least part of a system for performing amethod in one territory does not preclude use of the system in anotherterritory.

All of the above U.S. patents, U.S. patent application publications,U.S. patent applications, foreign patents, foreign patent applicationsand non-patent publications referred to in this specification and/orlisted in any Application Data Sheet are incorporated herein byreference, to the extent not inconsistent herewith.

One skilled in the art will recognize that the herein describedcomponents (e.g., operations), devices, objects, and the discussionaccompanying them are used as examples for the sake of conceptualclarity and that various configuration modifications are contemplated.Consequently, as used herein, the specific exemplars set forth and theaccompanying discussion are intended to be representative of their moregeneral classes. In general, use of any specific exemplar is intended tobe representative of its class, and the non-inclusion of specificcomponents (e.g., operations), devices, and objects should not be takenlimiting.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations are not expressly set forth herein for sakeof clarity.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely exemplary, and that in fact many other architectures may beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected”, or“operably coupled,” to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable,” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents, and/or wirelessly interactable, and/or wirelesslyinteracting components, and/or logically interacting, and/or logicallyinteractable components.

In some instances, one or more components may be referred to herein as“configured to,” “configurable to,” “operable/operative to,”“adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Thoseskilled in the art will recognize that such terms (e.g. “configured to”)can generally encompass active-state components and/or inactive-statecomponents and/or standby-state components, unless context requiresotherwise.

Although specific dependencies have been identified in the claims, it isto be noted that all possible combinations of the features of the claimsare envisaged in the present application, and therefore the claims areto be interpreted to include all possible multiple dependencies.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true spirit and scope of the subject matter described herein.It will be understood by those within the art that, in general, termsused herein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to claims containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, those skilled in the art will recognize that such recitationshould typically be interpreted to mean at least the recited number(e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that typically a disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms unless context dictates otherwise. For example, the phrase “Aor B” will be typically understood to include the possibilities of “A”or “B” or “A and B.”

With respect to the appended claims, those skilled in the art willappreciate that recited operations therein may generally be performed inany order. Also, although various operational flows are presented in asequence(s), it should be understood that the various operations may beperformed in other orders than those which are illustrated, or may beperformed concurrently. Examples of such alternate orderings may includeoverlapping, interleaved, interrupted, reordered, incremental,preparatory, supplemental, simultaneous, reverse, or other variantorderings, unless context dictates otherwise. Furthermore, terms like“responsive to,” “related to,” or other past-tense adjectives aregenerally not intended to exclude such variants, unless context dictatesotherwise.

1-36. (canceled)
 37. A system, comprising: a first plasmon routedefining region including a magnetically interactive portion responsiveto a first magnetic field to define a propagation route of a firstplasmon signal absent a separate routing structure.
 38. The system ofclaim 37 further comprising one or more magnetic field sourcesconfigured to produce the first magnetic field.
 39. The system of claim38 further comprising a processor, wherein the processor is operablycoupled to control the one or more magnetic field sources.
 40. Thesystem of claim 39 wherein the processor is operably coupled totemporally vary the one or more magnetic field sources.
 41. The systemof claim 39 wherein the processor is operably coupled to move the one ormore magnetic field sources.
 42. The system of claim 38 wherein the oneor more magnetic field sources includes an array of magnetic fieldsources, and wherein the array of magnetic field sources has a variablespatial configuration.
 43. The system of claim 42 wherein the array ofmagnetic field sources is operably coupled to a processor to change thespatial configuration.
 44. The system of claim 37 further comprising asource of input energy configured to produce the first plasmon signal.45. The system of claim 44 further comprising a processor, wherein theprocessor is operably coupled to control the source of input energy. 46.The system of claim 44 wherein the source of input energy is configuredto produce plasmon energy.
 47. The system of claim 44 wherein the sourceof input energy is configured to produce electromagnetic energy.
 48. Thesystem of claim 47 further comprising a converter configured to convertthe electromagnetic energy into plasmon energy.
 49. An apparatus,comprising: a first surface state support including an input locationand an output location, the first surface state support being defined bya boundary between a first material and a second material, wherein eachof the first material and the second material is optically thick; and afirst magnetically responsive structure interposed at a first centrallocation intermediate the input location and the output location, thefirst magnetically responsive structure being responsive to a magneticfield to control surface state propagation by establishing a firstpermittivity proximate to the first surface state support.
 50. Theapparatus of claim 49 wherein the first material includes a conductor,and wherein the first material has a first thickness in the range fromabout 1 micron to about 10 microns.
 51. The apparatus of claim 50wherein the second material includes a dielectric, and wherein thesecond material has a second thickness in the range from about 1 micronto about 10 microns.
 52. The apparatus of claim 49 wherein the firstmaterial includes a conductor, and wherein the first material has afirst thickness in the range from about 10 microns to about 100 microns.53. The apparatus of claim 49 wherein the first material includes aconductor, and wherein the first material has a first thickness in therange from about 100 microns to about 1 millimeter.
 54. The apparatus ofclaim 49 wherein the first surface state support is configured to allowsurface state propagation in a first frequency range, and wherein thefirst material and the second material are optically thick in the firstfrequency range.
 55. The apparatus of claim 54 wherein the firstfrequency range includes optical frequencies.
 56. The apparatus of claim49 wherein the first magnetically responsive structure is integral tothe first and second materials.
 57. The apparatus of claim 49 whereinthe input location is configured to convert electromagnetic energy tosurface state energy.
 58. The apparatus of claim 49 wherein the outputlocation is configured to convert surface state energy toelectromagnetic energy.
 59. An apparatus, comprising: a first photoniccrystal surface state support including an input location and an outputlocation, wherein the first photonic crystal surface state supportincludes an interface between a first photonic crystal and a secondmaterial; and a first magnetically responsive structure interposed at afirst central location intermediate the input location and the outputlocation, the first magnetically responsive structure being responsiveto a magnetic field to control surface state propagation by establishinga first permittivity proximate to the first photonic crystal surfacestate support.
 60. The apparatus of claim 59 wherein the first photoniccrystal includes a 1D photonic crystal.
 61. The apparatus of claim 59wherein the first photonic crystal includes a 2D photonic crystal. 62.The apparatus of claim 59 wherein the first photonic crystal includes a3D photonic crystal.
 63. The apparatus of claim 59 wherein the firstphotonic crystal includes a dielectric omnidirectional reflector. 64-78.(canceled)